资源环境科技发展态势分析平台

Using high‐resolution data from Magnetospheric Multiscale (MMS) mission, we report an in situ observation of a secondary reconnection electron diffusion region (EDR) beside the leading edge of an ion‐scale flux rope at the magnetopause. This reconnection EDR is characterized by strong electron current and electron jet reversal, a normal Hall electric field, unmagnetized electrons with non‐gyrotropic distributions, a large parallel electric field and strong energy dissipation. The ion‐scale flux rope beside the EDR consists of a force‐free structure with diameter of only ~3 ion inertial lengths. Our observation of secondary reconnection beside the flux rope gives further evidence that flux ropes can be created and evolved in the reconnection exhaust region.